Driving mechanism for drill presses



W. G. ALLEN. DRIVING MECHANISM FOR DRILL PRESSES.

APPLICATION FILED JULY 6. I921.

Patented Oct. 10,

atented Oct. 10, 1922.

WILLIAM G. ALLEN, or HARTFORD, ooivnncrrour.

DRIVING MECHANISM roe DRILL 'rnnssns.

Application filed July 6, 1921. Serial 116.482,?62.

ployed in drill presses forrotating the tool spindle. In these machinesthe spindlestands vertically in front and the driving shaft lieshorizontally lower down at the back of the frame. On the horizontalshaft is a driving pulley and on the vertical spindle or sleeve throughwhich the spindle extends is the driven pulley, these pulleysbeing conepulleys in order that the relative speeds of rotation of the shaft andspindle may be varied. In passing from the driving to the driven pulleysthe belt travels around guide pulleys usually mounted on abracket at theback near the top of the frame.

Changing the belt from a pulley step of one diameter to that of anotherfor varying the speed'of the spindle necessitates altering thehorizontal position of the guidepulleys'in order to keep the belt at theproper tension and zhanging thebelt from one step teenother step on thespindle or driven pulley reraising or lowering of the guide pulleys tothe level of the pulley step on which the belt isrun. In some priormachines this has been accomplished by raising or lowering the guidepulleys themselves and in other machines by changing the elevation ofthe bracket that carriesthe guide pulleys.

Theobject'of the present invention is to eliminate the complicatedmeehanismemployed to raise or lower the guidepulleysthemselvesandalsothe expensive and heavy construction necessarily usedwhere the guide pulley bracket israised and lowered, 4:5

easy to operate for aligning the spindle pulley with the guidepulleysand giving the belt theproper-tension." A

I This object is attained by arranging means for adjusting the guidepulleys horizontally for insuring the proper tension of'the belt,

andadjusting the spindle pulley vertically onthe spindle sleevein'orderthat thestep pulleys.

used may' properly align with the guide G. ALLEN,

8 having multiple steps. pulley restsupon anti-friction bearings 9 and"provide means which are simple and In the accompanying drawings, Figure1 shows a front elevatlon of the upper portion of a drill pressconstructed with mechanism that embodies the invention. Fig. 2 shows aside elevation of the same. Fig. 3 shows a topview of the press. Fig. atis a vertical section through the spindle pulley, sleeve and supportinghead. Fig. 5 is a horizontal section on the plane indicated by thedotted line 55 on Fig. 4. Fig. 6 shows an end view of the horizontallymovable guide pulley slide and its support. Fig. 7 shows in plan adetail of the means for adjusting the guide pulley slide. Fig. 8 showsin side elevation with a part in section, of a detail of the guidepulley slide adjusting means.

In the drawings only the upper portion of the base 1 of the frame isshown, as the base may have any ordinary design. Mounted on thetop ofthebase is the column 2 of suitable outline. This column at the top andback has an integral bracket 8 and at the front has a yoke-shaped head4:. In the upper and lower ends of the head are anti-friction bearings 5supporting a sleeve 6 through which passes the-tool spindle 7, the toolspindle, as is customary, being connected-to the sleeve by a spline sothatwlnle rotated by the sleeve it may have an independent verticalmovement as raised or lowered by the usual means. qu1res,1ntllBIIlElClllIlGS in common use, the

Splined on the sleeve so as to drive the sleeve but be capable ofindependent movement up and down thereon, is a cone pulley The hub ofthis supported by a yoke 10 that is fastened to the upper end of avertical bar 11. This bar is guided up and down in a bracket 12 fastenedto the head and it is provided with rack teeth l3 that are engaged by apinion let on a horizontal arbor which is carried by. a

sleeve 15 projecting forwardly from the lower end of the head. On thefront end of the arbor is a crank handle 16 and back of the handle andfastened to the sleeve is a disk 17 with stations 18 for stopping thebracket 3. Extending loosely through lugs 22 projecting downward fromthe under side of the slide near one edge is a rod 23. Threaded on therod outside of the rear lug are adjusting and clamping nuts 24; andthrusting between a nut 25 threaded on the rod and the other lug 22 is aspring 26. This spring normally holds the nuts 24 against theadjacentlug and it has a tension equal to that which it is required ofthe belt. The front end of the rod 23 is threaded and turning on thisthread is; a nut 27 bearing a pinion 28 (Fig. 7). Engaging with thispinion a pinlon 29 011 the end of a rod 30 that extends forwardly and issupported at the front of the machine by a sleeve 31 fastened to thehead. The front end of the rod 30 has a hand wheel 32. By turning thiswheel through the rods, pinions, spring and nuts, the slide carrying theguide pulleys may be adjusted horizontally toward or from the spindlepulley. When the tension of the belt" reaches that which is desired, thespring yields and the rod 23 moves through the lugs without carrying theslide. The tension of the spring is adjusted to the desired degree byturning the nut 25 up more or less on the rod 23. To prevent moretension being applied to the belt, a latch 33 is pivoted to the underside of the lug at the rear end of the rod 23 adjacent to the nuts 2dand a spring 3-l tends to engage the hooked end of this latch with aratchet toothed reel: .35 fixed to the bracket. Under norn'ialconditions the hooked end of the latch is held out of engagement withthe rack by the contact of the other end ofthe latch withthe nuts 24 011the rod 23 (Fig. 8), but when the tension of the spring is increased soas to be greater than the desired tension of the belt and the rod 23moves through the lugs and carries the nuts 24: away from the lug, thelatch is free to swing and engage with the rack and hold the slide fromfurther movement in such directionas to tend to increase the belttension, no matter how much the hand wheel is turned and the spring iscompressed.

With this construction the spindle pulley is easily and quickly raisedor lowered into exact position to have the belt 86 run around itproperly from the tops of the guide pulleys 19 over which the beltpasses from the cone pulley 87 on the driving shaft 38 that is supportedby a bracket 39 at the top of the base of the frame and that bearsapulley lO adapted to be connected with a source of power. The guidepulleys are readily adjusted to impart the necessary tension to the beltand when that tension is created the belt cannot be drawn any tighter.The handles for raising and lower ing the spindle pulley and foradjusting the guide pulleys are arranged at the front of the machine isconvenient position to be reached by the operator.

The invention claimed is 1. A driving mechanism for a drill presscomprising a rotatable sleeve held from vertical movement at the top infront of the fixed press frame, a cone pulley connected to rotate but tomove independently longitudinally on the sleeve, means for moving saidpulley longitudinally of the sleeve, guide pulleys mounted on horizontalaxes at the back of the top of the press frame, a drive pulley on ahorizontal axle mounted at the back of the press frame below the guidepulleys-,- and a belt passing around the drive pulley over the guidepulleys and around the sleeve pulley.

2. A driving mechanism for a drill press comprisinga vertical sleeverotatably supported in bearings fixed vertically at the front of thepress frame, a cone pulley movable up and down on, but connected torotate the sleeve, means for raising and lowering said pulley on thesleeve, guide pulleys mounted on horizontal axes at the back ofthe topof the press frame, a drive pulley on a horizontal axle mounted on theback of the press frame below the guide pulleys, and a belt passingaround the drive pulley over the guide pulleys and around the pulley onthe sleeve.

3. A driving mechanism for a drill press comprising a rotatable sleeveheld from vertical movement at the top in front of the fixed pressframe, a cone pulley connected to rotate but move independentlylongitudinally on the sleeve, means for adjusting said pulleylongitudinally on the sleeve, guide pulleys movable horizontally at theback of the top of the press frame, means for adjusting the guidepulleys backward and forward on the press frame, a. drive pulley on ahorizontal axle mounted at the back of the press frame below the guidepulleys, and a belt passing around the drive pulley over the guidepulleys and around the pulley on the sleeve.

4. A driving mechanism for a drill press comprising a rotatable sleeveheld from vertical movement with relation to the press frame, a eo nepulley connected to rotate but to move independently longitudinally onthe sleeve, means for adjusting said pulley longitudinally of thesleeve, swinging guide pulleys mounted on horizontal axes at the top ofthe back of the press frame, a cone drive pulley on a horizontal shaftmounted at the back of the press frame below the guide pulleys, and abelt passing around the drive pulley over the guide pulleys and aroundthe sleeve pulley.

5. A driving mechanism for a drill press comprising a rotatable sleeveheld from vertical movement with relation to the press frame, a conepulley connected to rotate but move independently longitudinally on thetool spindle, elevating mechanism supporting said cone pulley, means foroperating said elevating mechanism, guide pulleys mounted at the top ofthe back of the press frame, a drive pulley on a horizontal axle 'at'theback of the press frame below the guide pulleys, and a belt passingaround the drive pulley over the guide pulleys and around the pulleyonthe sleeve.

6. A driving mechanism for a drill press comprising a fixed head, asleeve rotatably supported by said head, a cone pulley located in saidfixed head and connected to rotate but move independently longitudinallyon the sleeve, elevating mechanism supporting said cone pulley, meansfor raising and lowering said elevating mechanism, guide pulleys mountedat the top of the back of the press frame, a drive pulley on ahorizontal.

axle at the back of the press frame below the guide pulleys, and abeltpassing around the drive pulley over the guide pulleys and upon saidslide, a drive pulley mounted on a horizontal axle at the back of thepress frame below the guide pulleys, and a belt passing around the drivepulley over the guide pulleys and around the pulley on the sleeve.

8. A driving mechanism for a drill press comprising 'a cone pulleyconnected to r0- tate but to move independently longitudinal of the toolspindle, means for moving said pulley longitudinally of the toolspindle. a slide movable horizontally on the top of the press frame atthe back, yielding means for moving said slide backward, means forpreventing the backward movement of the slide when the tension of saidyielding means is overcome, guide pulleys carried upon the slide, adriving pulley mounted on a horizontal axle at the back of the pressframe below the guide pulleys, and a belt around the drive pulley overthe guide pulleys and around the spindle pulley.

9. A drill press having a fixed head in the front at the top of theframe and a fixed bracket in the back at the top of the frame, a sleeverotatably mounted in said head, a cone pulley vertically movable in saidhead on the sleeve, mechanism for raising and lowering said pulley, aslide movable hori zontally on said bracket, mechanism for moving saidslide toward and from the head, guide pulleys swivelled on said slide, adriving pulley, and a belt passing around the driving pulley over theguide pulleys and around the sleeve pulley.

WILLIAM G. ALLEN.

